In this chapter, you learned important concepts and tools that you will probably use as your applications grow.

First, you saw the Heroku Postgres rollback. This is very useful when data loss occurs accidentally. With one command, you can create a new database with the old state of your main database.

You learned about working with follower databases. The followers probably will be one of the features that you will use as your application grows up. Through followers, Heroku created a master-slave solution for database reading.

Finally, you learned about fork databases. A fork is a copy of the database, and it isn't synchronized with the main database. You also learned that forks are interesting to experiment and test with different database plans.

In the next chapter, you will learn how logs work and how to extract information that helps you identify problems and understand the most common errors.